SE—Structures and Environment: Optimal Control Strategies for Carbon Dioxide Enrichment in Greenhouse Tomato Crops—Part 1: Using Pure Carbon Dioxide

doi:10.1006/bioe.2001.0039

Biosystems Engineering

Volume 81, Issue 4, April 2002, Pages 421-431

https://doi.org/10.1006/bioe.2001.0039 Get rights and content

Abstract

Two optimal control strategies for carbon dioxide (CO₂) enrichment in greenhouse tomato crops have been developed. One uses pure CO₂ from a storage tank and the other uses CO₂ contained in the exhaust gases of boilers burning natural gas. The optimal strategies maximize the financial margin between crop value and the combined costs of the CO₂ used for enrichment and the natural gas used for heating. In this paper, the strategy for optimal control using pure CO₂ is presented and compared with strategies used by growers. The optimal strategy for enrichment with exhaust gas derived CO₂ is presented in an accompanying paper. Simulations show that at a cost of £0·09 kg⁻¹ for pure CO₂ and £0·10 m⁻³ for natural gas, the optimal enrichment strategy would increase the annual margin of crop value over CO₂ and heating costs by £4·6 m⁻² (27%) compared to a basic control strategy of enrichment to a concentration of 1000 v.p.m. (parts per million by volume) when ventilators are <5% open, otherwise enrichment to 350 v.p.m. The optimal CO₂ concentration was expressed as an algebraic function of solar radiation, wind speed and ventilator opening angle, and so enabled a quasi-optimal value to be obtained using variables measured by greenhouse environmental controllers. The quasi-optimal equation, with coefficients averaged from simulations over 4 years, gave an increased margin over the basic control strategy of £4·4 m⁻² (26%).

References (19)

BJ Bailey et al.
Improving the cost effectiveness of greenhouse climate control
Computers and Electronics in Agriculture
(1994)
ZS Chalabi
A generalized optimization strategy for dynamic CO₂ enrichment in a greenhouse
European Journal of Operational Research
(1992)
ZS Chalabi et al.
A real-time optimal control algorithm for greenhouse heating
Computers and Electronics in Agriculture
(1996)
DL Critten
Optimisation of CO₂ concentration in greenhouses: a modelling analysis for the lettuce crop
Journal of Agricultural Engineering Research
(1991)
JE Fernandez et al.
Measurement and prediction of greenhouse ventilation rates
Agricultural and Forest Meteorology
(1992)
I Seginer et al.
Optimal CO₂ enrichment strategy for greenhouses, a simulation study
Journal of Agricultural Engineering Research
(1986)
B Acock et al.
The contribution of leaves from different levels within a tomato crop to canopy net photosynthesis: an experimental examination of two canopy models
Journal of Experimental Botany
(1978)
DP Aikman
A procedure for optimising CO₂ enrichment of a glasshouse tomato crop
Journal of Agricultural Engineering Research
(1996)
BJ Bailey
Wind dependent control of greenhouse temperature
Acta Horticulturae
(1985)

There are more references available in the full text version of this article.

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Poverty, food insecurity and climate change are global issues facing humanity, threatening social, economic and environmental sustainability. Greenhouse cultivation provides a potential solution to these challenges. However, some greenhouses operate inefficiently and need to be optimized for more economical and cleaner crop production. In this paper, an economic model predictive control (EMPC) method for a greenhouse is proposed. The goal is to manage the energy-water‑carbon-food nexus for cleaner production and sustainable development. First, an optimization model that minimizes the greenhouse's operating costs, including costs associated with greenhouse heating/cooling, ventilation, irrigation, carbon dioxide (CO₂) supply and carbon emissions taking into account both the CO₂ equivalent (CO₂-eq) emissions caused by electrical energy consumption and the negative emissions caused by crop photosynthesis, is developed and solved. Then, a sensitivity analysis is carried out to study the impact of electricity price, supplied CO₂ price and social cost of carbon (SCC) on the optimization results. Finally, a model predictive control (MPC) controller is designed to track the optimal temperature, relative humidity, CO₂ concentration and incoming radiation power in presence of system disturbances. Simulation results show that the proposed approach increases the operating costs by R186 (R denotes the South African currency, Rand) but reduces the total cost by R827 and the carbon emissions by 1.16 tons when compared with a baseline method that minimizes operating costs only. The total cost is more sensitive to changes in SCC than that in electricity price and supplied CO₂ price. The MPC controller has good tracking performance under different levels of system disturbances. Greenhouse environmental factors are kept within specified ranges suitable for crop growth, which increases crop yields. This study can provide effective guidance for growers' decision-making to achieve sustainable development goals.
Techno-economic analysis of a chemical looping combustion process for biogas generated from livestock farming and agro-industrial waste
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Biogas is a renewable fuel that is generated from the decomposition of organic matter through the process of anaerobic digestion. The compound that provides biogas with its energy value is CH₄, which accounts for between 40% and 75% of the gas, with CO₂ being the other main component of this fuel. Although the biogas valorization process is carbon neutral, the overall process can become carbon negative with the application of CO₂ capture technologies, such as chemical looping combustion (CLC). This work presents a techno-economic analysis of a 5 MW_th plant for the generation of biogas from livestock farming and agro-industrial waste to produce electricity + heat or heat only (base cases), or for further treatment in a CLC unit (CLC cases), where the captured CO₂ is converted into a raw material, e.g. for the production of greenhouse crops. Results from the comparative study of five different oxygen carriers used in CLC are also presented.
The profitability of the base cases was evaluated by means of the Levelized Cost of Electricity (LCOE) and Levelized Cost of Thermal Energy (LCOTE) metrics, whereas the economic performance of the CLC cases was measured by the Levelized Cost of CO₂ (LCOCO₂). LCOE gave a value of €139.90/MWh for the base case, and LCOTE was €56.50/MWh for the modified base case, where biogas was combusted in a boiler to produce only heat. With regard to the CLC cases, LCOCO₂ values ranged between €148.60 per tonne for a highly reactive, synthetic Cu-based oxygen carrier and €177.10 per tonne for ilmenite.
Finally, by comparing the economic results obtained in this work with those found in the literature for conventional biogas production plants and greenhouse crop production processes, it can be concluded that the implementation of CLC technology in biogas plants has the potential to become a profitable and environmentally sustainable option for the valorization of organic waste because the CO₂ generated in the fuel reactor of the CLC unit can be considered a marketable, high value-added product for the niche market of the greenhouse farming of horticultural crops.
Model predictive control of a Venlo-type greenhouse system considering electrical energy, water and carbon dioxide consumption
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Greenhouse systems consume lots of energy, water and carbon dioxide ( ${CO}_{2}$ ) to provide a suitable growth environment for crops. Due to the problems of operation mode, some greenhouse systems are inefficient and need to be optimized. In this paper, four optimization strategies for improving the operation efficiency of greenhouse systems are studied. Strategy 1 minimizes the energy consumed for greenhouse heating, cooling, ventilation and irrigation. Strategy 2 minimizes the water consumed for irrigation. Strategy 3 minimizes the ${CO}_{2}$ consumed for greenhouse ${CO}_{2}$ enrichment. Strategy 4 minimizes the total cost of energy, water and ${CO}_{2}$ consumed. These optimization strategies are based on a multi-input multi-output (MIMO) climate model and a modified evapotranspiration model. Moreover, a sensitivity analysis is conducted to study the influence of electricity price, water price, ${CO}_{2}$ price and the range of system constraints on the optimization results. Finally, a model predictive controller (MPC) is designed to reject system disturbances and address model plant mismatch. The MPC controller is compared with a commonly used open loop controller. A performance index relative average deviation (RAD) is introduced to evaluate the tracking performance of the proposed MPC and the compared open loop control. Simulation results show that Strategy 4 reduce the total cost by 66.60 %, 92.68 % and 68.83% compared with Strategy 1, Strategy 2 and Strategy 3 respectively. Changes in electricity price have a greater impact on optimization results than changes in water price and ${CO}_{2}$ price. Both temperature constraints and relative humidity constraints have a great influence on the optimization results. The controller designed is verified to be effective.
Effect of H<inf>2</inf>S and NH<inf>3</inf> in biomass gasification producer gas on CO<inf>2</inf> capture performance of an innovative CaO and Fe<inf>2</inf>O<inf>3</inf> based sorbent
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This study has investigated the effect of contaminants in biomass gasification producer gas on the CO₂ capture performance of an innovative CaO and Fe₂O₃ based sorbent material. It is well known that biomass gasification producer gas contains gaseous contaminants such as H₂S and NH₃. Experiments were conducted with the combined contaminants of H₂S at 230 ppmv and NH₃ at 2300 ppmv. Each run of the experiment included three major stages: H₂ reduction, CO₂ capture (carbonation) and CO₂ release (calcination). The operation temperature was controlled at 650 °C with a duration of 3 h at the carbonation stage, and at 850 °C with a duration of 2 h at the calcination stage. In each experiment, three cycles of carbonation-calcination were performed.
The experimental results show an average CO₂ capture efficiency of 61.8% during the carbonation stage in the first cycle, reducing to 45.4% in the third cycle. However, effective CO₂ capture was achieved in the initial 20 min of carbonation, with a capture efficiency of 75.1% for the first cycle and 62.8% in the third cycle.
It was found that the CO₂ sorbent can effectively remove contaminants from the producer gas, showing catalytic effect of the sorbent material. The H₂S removal efficiency decreased from 99% in the first cycle to 82% after three cycles, while the NH₃ removal efficiency was above 99% for all three cycles during the carbonation stage. Furthermore, concentrations of the N-based and S-based compounds in the outlet gas streams during calcination were examined for the potential impact when the gas is injected into plant nursery greenhouses for growth enhancement. Fundamental analysis was also performed and microstructural changes in the material were examined to understand the CO₂ capture process by the tested sorbent.
CO<inf>2</inf> utilisation in agricultural greenhouses: A novel ‘plant to plant’ approach driven by bioenergy with carbon capture systems within the energy, water and food Nexus
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Citation Excerpt :
The multi-objective optimisation considered the economic and environmental dimensions of the distribution network, which is comprised of pipeline and road routes. Previous studies have investigated CO2 utilisation in agricultural greenhouses, emphasising the design and optimisation of CO2 enriched greenhouses, with the consideration of commercial CO2 or in-house combustion as a source [35–39]. However, CO2 can be obtained from different systems and applications, which engenders different economic costs and environmental burdens related to the capture, handling, transportation and consequently the utilisation of CO2.
Securing the growing populations' demand for food energy and water whilst adapting to climate change is extremely challenging. In this regard, bioenergy coupled with carbon capture and storage or utilisation (BECCS/U) is an attractive solution for meeting both the population demand, and offsetting CO₂ emissions. The purpose of this study is to evaluate the effectiveness of BECCS/U pathways utilising CO₂ for agricultural enrichment in enhancing food systems and reducing GHG emissions within the energy, water and food nexus concept. The study bridges negative emissions with CO₂ fertilisation within an integrated system. It consists of a source of CO₂ represented by a biomass-based integrated gasification combined cycle with carbon capture, a CO₂ network for a sustainable CO₂ supply, and a CO₂ sink characterised by agricultural greenhouses. A techno-economic and environmental analysis of each of these subsystems is conducted, feeding to an overall performance analysis of the integrated BECCS/U pathway. Results reveal synergetic opportunities between the energy, water and food subsectors, whereby CO₂ is captured from an energy sub-system and is efficiently utilised to enhance food sub-systems by improving productivity and reducing crop water requirements. Thus, the proposed integrated BECCS/U system is able to improve food availability by enhancing the food system, increasing the yield by 13.8%, whilst reducing crop water requirements by 28%. System outputs resulted in a levelised cost of 0.35 $/kg of agricultural produce when the system is scaled-up, and an abatement of the related environmental burdens throughout the supply chain by achieving negative CO₂ emissions of 24.6 kg/m².year of cultivated land.
CO<inf>2</inf> sensing with gas sensors based on rare-earth compounds: Material exploration
2020, Sensors and Actuators, B: Chemical
Rare-earth oxycarbonates Ln₂O₂CO₃ (Ln = rare-earth element) have been identified as materials for chemoresistive CO₂ gas sensors. Among them, previous studies identified monoclinic La₂O₂CO₃ as the best performing one. However, not all rare-earth elements have been investigated and, moreover, La₂O₂CO₃ monoclinic phase is metastable and this can influence the long term performance. In this work, we have synthesized rare-earth oxycarbonates Ln₂O₂CO₃ (Ln = La, Nd, and Sm) including monoclinic and hexagonal La₂O₂CO₃, rare-earth oxides Ln₂O₃ (Ln = Nd, Sm, Gd, Dy, Er, and Yb) and LnO₂ (Ln = Ce) by calcination of oxalate hydrate or the acetate hydrate precursors in air. All the materials, except for CeO₂ and Nd₂O₃, were sensitive to CO₂. All CO₂ sensitive materials, except for monoclinic La₂O₂CO₃ and Nd₂O₂CO₃, were stable and their performance is sufficient for practical use. Hexagonal La₂O₂CO₃ shows the best overall performance. The results of operando investigations indicate that the origin of CO₂ sensing is the competitive adsorption between carbonates and hydroxyl groups.

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Regular ArticleSE—Structures and Environment: Optimal Control Strategies for Carbon Dioxide Enrichment in Greenhouse Tomato Crops—Part 1: Using Pure Carbon Dioxide

Abstract

Computers and Electronics in Agriculture

European Journal of Operational Research

Computers and Electronics in Agriculture

Journal of Agricultural Engineering Research

Agricultural and Forest Meteorology

Journal of Agricultural Engineering Research

The contribution of leaves from different levels within a tomato crop to canopy net photosynthesis: an experimental examination of two canopy models

Journal of Experimental Botany

A procedure for optimising CO2 enrichment of a glasshouse tomato crop

Journal of Agricultural Engineering Research

Wind dependent control of greenhouse temperature

Acta Horticulturae

Regular Article
SE—Structures and Environment: Optimal Control Strategies for Carbon Dioxide Enrichment in Greenhouse Tomato Crops—Part 1: Using Pure Carbon Dioxide

A procedure for optimising CO₂ enrichment of a glasshouse tomato crop