A Study on Recycling of Spent Mushroom Substrate to Prepare Chars and Activated Carbon

Abstract

a Chars were obtained from spent mushroom substrate (SMS) via pyrolysis. It was found that as the pyrolysis temperature increased from 400 to 700 °C, the char yield decreased from 45.10 to 33.79 wt.% and the higher heating value increased from 17.32 to 22.72 MJ/kg. The largest BET surface area (13 m 2 /g) was created at 500 °C. Hydrogen atoms were continuously lost during pyrolysis, whereas oxygen atoms were difficult to eliminate. Whewellite, calcite, lime, and quartz were the minerals in the chars, and their forms and crystallinity changed with changing pyrolysis temperature. Activated carbon with a BET surface area of 1023 m 2 /g and a total pore volume of 0.595 cm 3 /g was obtained from the char prepared at 500 °C. Its characteristics were studied by N2-adsorption, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The pyrolysis and KOH-activation processes were investigated by thermogravimetric analysis (TGA). The results showed that the pyrolysis of SMS occurred primarily between 217 and 375 °C and that the energies needed for the pyrolysis reactions were relatively low due to the prior mushroom cultivation. Furthermore, lignin was incompletely decomposed in the char prepared at 500 °C, and KOH suppressed tar evolution and reduced the energy needed to decompose the residual lignin during activation.

Microwave vacuum pyrolysis conversion of waste mushroom substrate into biochar for use as growth medium in mushroom cultivation

“…The relatively small weight reduction between 110 ∘ C and 250 ∘ C could be caused by the decomposition of small organic molecules, for instance, amino acids and fatty acids produced within the SMS during the cultivation of mushroom. 30 At temperatures between 265 ∘ C and 380 ∘ C, there was a dramatic drop in the weight of SMS (nearly 49%). This was because of devolatilization resulting from the degradation of lignin, hemicellulose, and cellulose components in the SMS into smaller compounds.…”

“…The figure shows that there was a sharp weight reduction at around 100 °C caused by the evaporation of adsorbed water within the SMS. The relatively small weight reduction between 110 °C and 250 °C could be caused by the decomposition of small organic molecules, for instance, amino acids and fatty acids produced within the SMS during the cultivation of mushroom …”

Pengetahuan agropreneur terhadap potensi sisa substrat cendawan dan kaedah pengurusan lepas tuai tanaman cendawan

“…Kelebihan ini menjadikannya mampu untuk mengekalkan kualiti bahan organik atau sumber nutrien yang terdapat dalam sisa substrat tersebut (Ahlawat & Sagar, 2011). Kandungan nilai nutrien iaitu nitrogen (N), fosforus (P) dan potassium (K) dalam SMS sangat efektif dimajukan sebagai baja organik atau kompos dan vermikompos (Ahlawat & Sagar, 2007;Grimm & Wȍsten, 2018;Nik Nor Izyan et al, 2009;Ma, et al, 2014). Baja organik ini amat sesuai untuk pembangunan sub sektor pertanian terutamanya tanaman hortikultur serta herba (Ahlawat & Sagar, 2007;Ahlawat & Tewari, 2007;Marshall & Nair, 2009;Marques et al, 2014;Zhang et al, 2014).…”

“…SMS juga mampu bertindak sebagai sumber alternatif kepada bahan api fosil. Kajian oleh Oei et al (2007), Ma et al (2014) dan Pérez-Chávez et al (2019) mendapati SMS telah dibangunkan dengan jayanya sebagai sumber bahan bakar, pengegasan (gasification) (Finney et al, 2009), biogas dan gas metana untuk tujuan pemanasan dan bahan api domestik. Menurut Meera et al (2014), penghasilan biogas daripada SMS ini berupaya menjimatkan penggunaan tenaga elektrik di kawasan luar bandar.…”

“…Majoriti agropreneur adalah berbangsa Melayu iaitu 91.7% di Kedah dan 71.4% di Johor, manakala selebihnya adalah berbangsa Cina (Jadual 1). (Ahlawat & Sagar, 2007;Grimm & Wȍsten, 2018;Nik Nor Izyan et al, 2009;Ma et al, 2014). Begitu juga penggunaan SMS sebagai vermikompos yang hanya diketahui penggunaannya oleh tujuh orang agropreneur (19.4%) di Kedah dan lima orang agropreneur (26.2%) di Johor (Jadual 3).…”