Assessment of hemp hurd-derived biochar produced through different thermochemical processes and evaluation of its potential use as soil amendment.

Biochar is a carbon-rich and porous material that finds application in different sectors and can be extremely useful in agriculture as soil improver. This paper provides a comparison between biochars produced with different slow pyrolysis processes and biochar produced in a downdraft gasifier. A blend of residual lignocellulosic biomasses (hemp hurd and fir sawdust) was pelletized and used as starting feedstock for the tests. The biochars produced were analyzed and compared. Temperature proved to be the main driver in conditioning the chemical-physical characteristics of the biochars more than residence time or the configuration of the pyrolysis process. The higher the temperature, the higher the carbon and ash content and the biochar pH and the lower the hydrogen content and the char yield. The most noticeable differences between pyrolysis and gasification biochars were the pH and the surface area (considerably higher for gasification char) and the low content of hydrogen in the gasification biochar. Two germinability tests were carried out to assess the possible application of the various biochars as soil amendment. In the first germinability test, watercress seeds were placed in direct contact with the biochar, while in the second they were placed on a blend of soil (90%v/v) and biochar (10%v/v). The biochars with the best performance were those produced at higher temperatures using a purging gas and the gasification biochar (especially mixed with soil).

Effects of different gasification biochar grain size on greenhouse gases and ammonia emissions in municipal aerated composting processes.

This work is aimed at investigating the effects derived from the application of minimum amounts of two different sized biochars, obtained through biomass gasification, on the greenhouse gases and ammonia emissions from a co-composting process of the organic fraction of municipal solid waste. The chosen biochar-to-organic waste share is set to 3% w/w dry, and the results obtained are compared with a conventional composting process without biochar. Nine aerated static pilot-scale bins with a volume of 1.3 m3 were prototyped and run, three per thesis and three for the control. The trial lasted 63 days, following the same approach used in full-scale composting facilities. The testing period was divided into a forced aeration phase followed by a static phase. In terms of global warming potential, the use of fine biochar and coarse biochar resulted in 13 and 11 kg CO2eq ton-1 emitted respectively. These values are 36% and 45% lower than the 20 kg of CO2eq ton-1 emitted by the control theses. Specifically, the chosen minimum amounts of biochar produced a reduction of CH4 and N2O, while a significant reduction in NH3 emissions was not detected. Carbon dioxide showed a slight increase in biochar theses. This work has proven that fine and coarse gasification-derived biochars improve the bio-oxidative phenomena and reduce greenhouse gases emissions of the composters, regardless of the biochar particle size and regardless of the modest 3% w/w biochar-to-organic waste share used.

Enrichment of wheat flour with Spirulina. Evaluation of thermal damage to essential amino acids during bread preparation.

Microalgae and cyanobacteria represent a sustainable and valuable source of essential amino acids and bio-active molecules (e.g. poly-unsaturated fatty acids and antioxidants) which, if added to staple food, could enrich its nutritional profile and the human diet. In this study, two different composite mixtures were obtained by adding different percentages (1% and 2%) of Spirulina powder to "Italian type 1" semi-whole wheat flour (W = 300) after which the chemical, physical, alveographic, and rheological parameters were subsequently analyzed. Spirulina powder did not cause drastic changes at the rheological level when added up to 2%. Furthermore, the concentration of proteins significantly increased in the samples enriched with 1% Spirulina (3.17%) and 2% Spirulina (5.12%), while at the same time the gluten content decreased by 5.62% and 7.41%, respectively. The total amount of essential amino acids in the samples enriched with 1% and 2% Spirulina (48,209 and 55,286 mgaa/kgDW, respectively), was higher in comparison with 45,433 mgaa/kgDW of the control, and those concentrations were maintained after the baking process. Spirulina powder confirmed the hypothesis of being able to improve the supply of essential amino acids that is lacking in wheat flour. The next steps include an investigation into the sensory and liking characteristics of the product.

Experimental methodology for quantitative assessment of heat-wrap thermal transient behavior.

Among the numerous thermotherapy methods, heat wraps have been largely used over the last 2 decades as a self-administered practice for pain relief. Therefore, understanding their performance has become instrumental within the healthcare industry. However, the majority of the available studies have been focused on in vivo clinical performance, whereas a standardized, quantitative approach to evaluate and compare the various heat-wrap types against each other is lacking. An experimental methodology is proposed to carry out a comparative assessment between heat wraps in terms of their transient thermal behavior. A simple setup was developed to measure wrap/substrate interface temperature trend. The approach was validated by a preliminary infrared-thermography assessment and statistical analysis on the extensive dataset acquired on commercial heat-wrap types for low-back and neck pain relief. The heat-release trend was found to be qualitatively similar over all the investigated types, consisting of rapid growth, stationary phase, decay and end of the reactions. A set of parameters is also proposed to summarize heat-wrap thermal performance.