Moriyasu Nonaka

The Hot Compressed Water Treatment of Solid Waste Material from the Sugar Industry for Valuable Chemical Production

Sugarcane bagasse, the solid waste material produced in the sugar industry, was subjected to treatment in hot compressed water. The experiments were performed in a batch-type reactor containing slurry of 10 ml of water and 1.2 g of solids. The reactor was heated to temperatures ranging between 200°C and 300°C for reaction times of 3 to 30 min. The product was separated into liquid and solid fractions. Each fraction was analyzed to investigate the alteration of the main lignocellulosic polymers by hot compressed water. Results for the liquid fractions showed that increased temperatures and reaction times completely dissolved hemicellulose and cellulose in the water, leaving lignin in the solid product. During treatment, hemicellulose and cellulose gradually decomposed into simple sugars, which were then degraded and decomposed into furfural, 5-(hydroxymethyl)furfural (5-HMF) and organic acids. However, the yield of furans and some organic acids decreased and became undetectable at 300°C and with increasing reaction time. The solid fraction was also characterized before and after treatment. Results showed that the hydrogen and oxygen content of the solids decreased with increased reaction conditions, due to dehydration and decarboxylation reactions. The reactions also increased the carbon content of the treatment products by 1.2–1.6 times that in the raw material, suggesting that the hot compressed water treatment of sugarcane bagasse can be considered for the provision of valuable chemicals for biofuel and high-carbon-content material (biochar).

Use of FTIR combined with forms of water to study the changes in hydrogen bonds during low-temperature heating of lignite

ABSTRACT The changes in the hydrogen bonds (HBs) of three types of Indonesian lignite during low-temperature heating were investigated. The amount of water loss was determined by weighing the samples before and after heating in an oven. The changes in the number of the different types of HBs were determined using Fourier transform infrared spectroscopy coupled with types of water in lignite. The number of peak positions and absorption bands in each spectrum was determined by curve-fitting analysis with a Gaussian function. The quantified integrated area of aromatic hydrogen atoms was used to accurately investigate the changes in the HBs. The results show that at low temperatures (T ≤ 50°C), free water is mainly removed, and the HBs broken are those between free water molecules. However, at medium temperatures (50 <T ≤ 100°C), bound water is mainly removed. The number of HBs significantly changes because of the breaking of bound water molecule HBs and bound water cluster–carboxyl group HBs, and the formation of nonfreezable moisture HBs. At high temperatures (100 <T < 125°C), nonfreezable moisture can be released. The number of HBs changes as a result of competition between the removal of nonfreezable moisture and the increase in the number of carboxyl groups. At higher temperatures (T ≥ 125°C), the moisture remaining in lignite is thermal decomposition moisture. In addition, the rate of decomposition of carboxyl groups is higher than the rate of generation, which means that the number of HBs markedly decreases at higher temperatures.

Hydrothermal treatment coupled with mechanical expression for Loy Yang lignite dewatering and the microscopic description of the process

ABSTRACT The changes in the gaseous, liquid, and solid products obtained from hydrothermally treated lignite and hydrothermally treated solid products treated by the following mechanical expression were investigated. Furthermore, a microscopic description of the changes was present. Gaseous, liquid, and solid products were characterized by gas chromatography, total organic carbon analyzer, inductively coupled plasma atomic emission spectroscopy, high-performance liquid chromatography, and Fourier transform infrared spectrometer, respectively. The results showed that at temperatures above 173°C for hydrothermal treatment, freezable water, and some organic and inorganic compounds were removed from lignite, and acidic groups first dissolved and decomposed at 100°C. For the following mechanical expression treatment, freezable and nonfreezable water and organic and inorganic compounds were removed, and the concentration of acidic groups changed little. Within temperatures range 175–250°C, for hydrothermal treatment, nonfreezable water and inorganic and organic compounds continued to be removed, and the detection of CO2 is because of decarboxylation. For the following mechanical expression treatment, the main removed water was nonfreezable water, and changes in organic and inorganic compounds, acidic groups, and volatile matter were similar to that of samples treated by mechanical expression at temperatures below 173°C.

Application of plasma treated activated carbon to enhancement of phenol removal by ozonation in three-phase fluidized bed reactor

Plasma treatment of activated carbon (AC) was found to be an efficient method to enhance phenol removal by ozonation in a three-phase fluidized-bed reactor. The plasma treatment extended porous structure, changed surface morphologies, and produced oxygen functional groups on the surface of AC. Plasma-treated activated carbon together with O3 gave the best removal result, in which phenol was completely decomposed within 10 min (with pseudo first-order rate constant k = 0.286 min1), while untreated AC without O3 showed the worst result (k = 0.024 min1). Consequently, AC modified by plasma was shown to be a good material for removal of organic pollutants and yield superb performance in an integrated process with ozone in a fluidized-bed reactor.

Recovery of Non-Ferrous Metals from Car Scrap using the Jig Separator (ECHO Metal Jig, Type-SP).

Today, the non ferrous metals such as copper, brass, lead and zinc in car scrap are not systematically recovered, although the iron and the aluminum contained in car scrap are recovered. Therefore, for the recycling of resources and the preservation of natural environment, we started to make a study of recovery system of the non ferrous metals from the car scrap. In this paper, we conducted the separation experiments by using the ECHO Metal Jig (Type-SP) with jig box having the dimension of 250mm in width, 250mm in length and 300 mm in height, which is particularly made for an experimental purpose. And -10mm shredder dust abandoned in the scrap factory is treated with this jig and separated into three products (non metal dust, middling and non ferrous metal concentrate). The effect of gate height, feed speed and pulsation time for middling separation has been investigated.The results obtained through the experiments are summarized as follows;(1) The gate height at middling separation; Most effective factor is the gate height at middling separation.When the gate height is higher, the weight and the recovery of concentrate increase and the grade of that decreases, and vice versa.(2) The feed speed; Throughout this test, 0.54kg/s of feed speed gives maximum concentrate recovery and the best separation performance.(3) The Pulsation time for middling separation; The pulsation time for middling separation has no effect on the grade, recovery of the concentrate and the separation performance.(4) The best operating condition of this jig is as follows; 200mm of gate height at middling separation, 20s of pulsation time for middling separation and 0.54kg/s of feed speed.(5) This jig is very effective for -10mm shredder dust, since over 90% of valuable metals having over 7.0 of specific gravity is recoverable with this jig separator.

Recovery of Non-Ferrous Metals from Car Scrap using the Jig Separator (ECHO Metal Jig, Type-SP)

Up to now, Recycling of –10 mm size fraction of shredded car scrap has never been envisaged. To explore the possibility of this process, a study has been performed on this fraction using ECHO Metal Jig (Type-SP), particularly made for an experimental purpose. The results show that the valuable metals are effectively recovered from the –10 mm shredder dust.