Briquettes of plant remains from the greenhouses of Almería (Spain)

Abstract

Since ancient times, plant biomass has been used as a primary fuel, and today, with the impending depletion of fossil fuels, these vegetal sources constitute a cleaner alternative and furthermore have a multitude of uses. The aim of the present study is to design a method of recycling and reuse of plant wastes from intensive agriculture under plastic, by manufacturing briquettes in an environmentally friendly manner. In Almería (SE Spain), agriculture generates 769,500 t year -1 of plant remains from greenhouse-grown horticultural crops, a resource currently used for composting and for producing electricity. With the machinery and procedures of the present study, another potential use has been developed by detoxifying and eliminating the plastic wastes of the original biomass for the fabrication of briquettes for fireplaces. The results were slightly inferior to the commercial briquette from other non-horticultural plant materials (no forestry material), specifically 2512 kJ kg -1 , in the least favourable case. On the contrary, the heating value with respect to the two charcoals was significantly lower, with a difference of 12,142 kJ kg -1 . In conclusion; a procedure, applicable in ecological cultivation without agrochemicals or plastic cords, has been developed and tested to reuse and transform plant materials from intensive cultivation into a stable non-toxic product similar to composite logs, applicable in commercial settings or in residential fireplaces.Additional key words: biomass, contamination, horticulture, recycling. Resumen Briquetas de residuos vegetales procedentes de los invernaderos de Almería (España)Desde antaño, la biomasa vegetal se ha utilizado como combustible primario, es más, hoy en día con la disminución de combustibles fósiles es una alternativa más limpia que éstos y con multitud de usos. El objetivo de este trabajo es diseñar un método de reciclado y reutilización de residuos vegetales procedentes de la agricultura intensiva bajo plástico, mediante la fabricación de briquetas, todo ello respetando el medio ambiente. En Almería (sureste de España), la agricultura es capaz de generar 769.500 t año -1 de restos vegetales procedentes de cultivos hortícolas en invernadero, siendo usados actualmente para la obtención de electricidad y compost. Con la maquinaria y procedimientos del presente estudio se ha desarrollado otro posible uso, destoxificando y eliminando los residuos plásticos de la biomasa original para la fabricación de briquetas, y poder destinarlas para combustible de hogares. Los resultados son levemente inferiores a la briqueta comercial procedente de otro residuo vegetal hortícola (no forestal), concretamente de 2.512 kJ kg -1 , en el caso más desfavorable. Por el contrario, el poder calorífico respecto a los dos carbones comunes es significativamente menor, con una diferencia de 12.142 kJ kg -1 . En conclusión, se ha desarrollado y experimentado un procedimiento que permite reutilizar y transformar, a partir de métodos de cultivo ecológico sin agroquímicos y rafias ...

Prediction models for higher heating value based on the structural analysis of the biomass of plant remains from the greenhouses of Almería (Spain)

“…while generally producing some type of biomass waste. This biomass (from the above systems) can be used for energy but need to be studied from the logistical-environmental standpoint [5][6][7][8][9][10][11][12][13], analysed from the physical-chemical perspective [14][15][16], and submitted to different transformations (physical or chemical), to produce so-called biofuels [17][18][19][20][21][22].…”

The Management of Agricultural Waste Biomass in the Framework of Circular Economy and Bioeconomy: An Opportunity for Greenhouse Agriculture in Southeast Spain

“…Although their high moisture content reduces their caloric value [113] and makes them inefficient for biofuel production and gasification processes [61,114], some investigations suggest that combined heating and carbonic enrichment systems for greenhouses could be implemented by exploiting the combustion of these materials [115,116]. Perhaps, this alternative could also justify the production of other high added value bioproducts [61] using this waste material, such as the manufacturing of briquettes for household heating systems [117] and as a by-product for animal feed [118].…”

Characterization of ashes from greenhouse crops plant biomass residues using X‐ray fluorescence analysis and X‐ray diffraction

“…This surface is dedicated to the production of melons, watermelons, cucumbers, beans, peppers, lettuces, aubergines, courgettes, and tomatoes, which represent nearly 100% of the crops grown in Almería's greenhouses . From this, a large amount of crop residues are originated, with estimations of ~800,000 t/year (fresh weight) . The generated greenhouse crop residues are estimated in 235,544 t/year on dry basis .…”

“…[3] From this, a large amount of crop residues are originated, with estimations of 800,000 t/year (fresh weight). [3] The generated greenhouse crop residues are estimated in 235,544 t/year on dry basis. [8] An additional environmental problem appears when these residues are deposited in an uncontrolled way.…”

“…Greenhouse crop residues from Almería (SE Spain) have been studied as an interesting source of renewable energy. [2][3][4][5][6][7][8] The energy potential has been reported, and models have been developed for the prediction of their higher heating value of biomass materials. [6,7] In any case, ashes are generated.…”