(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2017/116773 Al 6 July 2017 (06.07.2017) W P O P C T (51) International Patent Classification: 85008-3279 (US). SHULT, Nicholas S.; 2255 North 44th C23F 1/14 (2006.01) H05K 3/38 (2006.01) Street, Suite 300, Phoenix, Arizona 85008-3279 (US). C01B 15/08 (2006.01) C09G 1/00 (2006.01) GOLDSMITH, Adam T.; 2255 North 44th Street, Suite 300, Phoenix, Arizona 85008-3279 (US). (21) International Application Number: PCT/US20 16/0673 13 (74) Agent: ROSENFIELD, Susan Stone; Fennemore Craig, 2394 East Camelback Road, Suite 600, Phoenix, Arizona (22) International Filing Date: 85016 (US). 16 December 2016 (16. 12.2016) (81) Designated States (unless otherwise indicated, for every (25) Filing Language: English kind of national protection available): AE, AG, AL, AM, (26) Publication Language: English AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, (30) Priority Data: DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, 62/273,389 30 December 201 5 (30. 12.2015) US HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KH, KN, 15/380,702 15 December 201 6 (15. 12.2016) US KP, KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, (71) Applicant: TESSENDERLO KERLEY, INC. [US/US]; MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, 2255 North 44th Street, Suite 300, Phoenix, Arizona NI, NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, 85008-3279 (US). RU, RW, SA, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, (72) Inventors: HOJJATIE, Michael Massoud; 2255 North ZA, ZM, ZW. 44th Street, Suite 300, Phoenix, Arizona 85008-3279 (US). LOCKHART, Constance Lynn Frank; 2255 North 44th (84) Designated States (unless otherwise indicated, for every Street, Suite 300, Phoenix, Arizona 85008-3279 (US). DI- kind of regional protection available): ARIPO (BW, GH, MITRIADIS, Alexandres; 2255 North 44th Street, Suite GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, 300, Phoenix, Arizona 85008-3279 (US). CLARKSON, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, Mark P.; 2255 North 44th Street, Suite 300, Phoenix, Ari TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, zona 85008-3279 (US). KOMINSKI, Harry Charles; 2255 North 44th Street, Suite 300, Phoenix, Arizona LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, 85008-3279 (US). VAN CAUWENBERGH, Jeroen; GW, KM, ML, MR, NE, SN, TD, TG). 2255 North 44th Street, Suite 300, Phoenix, Arizona [Continued on nextpage] (54) Title: SULFUR DIOXIDE SCRUBBING SYSTEM AND PROCESS FOR PRODUCING POTASSIUM PRODUCTS (57) Abstract: The invention relates to a process for preparing potassium thiosulfate, potassium sulfite or potassium bisulfite com prising the following steps: Step (la): providing a potassium hydroxide or potassium carbonate solution for neutralizing acid form ing components such as dissolving S0 2 or H2S; Step (lb): providing an S0 2 contacting solution, containing at least some potassium sulfite or potassium bisulfite or potassium thiosulfate; Step (2): providing SO2 gas; Step (3): reacting these to absorb the SO2 gas and o to form an intermediate reaction mixture comprising potassium sulfite, or potassium bisulfite or a mixture thereof, and optionally re covering the potassium sulfite, or potassium bisulfite or a mixture thereof, and/or optionally using steps 4 and 5; Step (4): adding sulfur or sulfide containing compound containing sulfur having the oxidation state of 0, -2 or of between 0 and -2 to the reaction o mixture and optionally potassium hydroxide or potassium carbonate, and reacting the mixture under suitable conditions to form po tassium thiosulfate; and Step (5): recovering the potassium thiosulfate, and optionally concentrating the potassium thiosulfate. w o 2017/116773 Al II 11 II I 1 I 1 II I II III II llll III II I II Declarations under Rule 4.17: Published: — as to applicant's entitlement to apply for and be granted — with international search report (Art. 21(3)) a patent (Rule 4.1 7(H)) TITLE OF THE INVENTION SULFUR DIOXIDE SCRUBBING SYSTEM AND PROCESS FOR PRODUCING POTASSIUM PRODUCTS CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. provisional application no. 62/273,389 filed on December 30, 2015, and U.S. nonprovisional application no. 15/380,702 filed on December 15, 2016, which are hereby incorporated herein by reference for all that they each disclose. FIELD OF THE INVENTION [0002] The present invention relates to a process for the preparation of potassium thiosulfate, or potassium sulfites and/or potassium bisulfites. BACKGROUND OF THE INVENTION 2 ~ 2 [0003] The thiosulfate ion, S20 , is a structural analogue of the S0 4 ion in which one ~2 oxygen atom is replaced by one S atom. However, the two sulfur atoms in S20 are not equivalent. One of the S atoms is a sulfide-like sulfur atom that gives the thiosulfate its reducing properties and complexing abilities. 0 S 1 I S S 0 < > 0::::::S::::::0 I I o _ o _ [0004] Thiosulfates are used in leather tanning, paper and textile manufacturing, flue-gas desulfurization, cement additives, dechlorination, ozone and hydrogen peroxide quenching, coating stabilizers, as an agricultural fertilizer, as a leaching agent in mining, and so on. [0005] Due to these complex-forming abilities with metals, thiosulfate compounds have also been used in commercial applications such as photography, waste treatment and water treatment applications. [0006] Thiosulfates do however readily oxidize to dithionates, trithionates, tetrathionates, and finally to sulfates: 2 → 2 2S 0 3 -+ 30 2S 0 - 2 → 2 S20 - + 0 2 2S0 4 2 → 2 2 ~ 7S20 3 + 3/202 2S30 +2S40 2 ~ → 2 ~ 2S 0 + 60 2 6S0 4 2 ~ → 2 ~ S40 + 50 2 4S0 4 [0007] Due to this transformation, thiosulfates are used as fertilizers in combination with cations such as ammonium, potassium, magnesium and calcium. The ammonium, alkali metal and alkaline earth thiosulfates are soluble in water. Water solubilities of thiosulfates decrease from ammonium to alkali metals to alkaline earth thiosulfates. [0008] Potassium (K) is a primary plant nutrient. Potassium is associated with movement of water, nutrients, and carbohydrates in plant tissue. If potassium is deficient or not supplied in adequate amounts, growth is stunted and yields are reduced. Potassium stimulates early growth, increases protein production, improves the efficiency of water use, is vital for stand persistence in cold weather, and improves resistance to disease and insects. [0009] Potassium thiosulfate fertilizer contains the highest percentage of potassium in liquid form, compared to other sources of potassium such as potassium chloride (KC1), potassium nitrate (KN0 ), and potassium sulfate (K2S0 4). In addition, it combines potassium with sulfur (17%) which is also an essential plant nutrient. [0010] It is contemplated that potassium thiosulfate could be produced by several alternative routes such as: I. Reaction of S and S0 2 in neutral or alkaline medium 2 2 2 II. Reaction of S and S0 (via S0 2 and HS0 ) III. Oxidation of Potassium Hydrosulfide (KSH) . Ion Exchange reaction between alkaline thiosulfates and potassium chloride or nitrate V. Salt exchange between alkaline thiosulfates and Potassium Chloride or Nitrate VI. Oxidation of Potassium Polysulfide [0011] However, some of these alternatives present serious difficulties or disadvantages. Route I and II are longer processes and require the use of sulfur dioxide S0 2. Both these routes are described when the scrubbing of the air pollutant sulfur dioxide is an objective. Route III requires handling of potassium hydrosulfide as a raw material which is not favorable due to a hydrogen sulfide environment. Routes IV and V suffer from the drawback that ion exchange and salt exchange require expensive raw materials and equipment, and also require a step of final stripping due to the need for working with dilute solutions. The prior art has been unsuccessful producing high purity potassium thiosulfate via Route VI with low byproducts. Thiosulfates, in general, are susceptible to further conversion to sulfite and sulfate under adverse temperature, and pressure. SUMMARY OF THE INVENTION [0012] Described herein are processes, preferably continuous, for the preparation of potassium thiosulfate in relatively high concentration with relatively low amounts of soluble or solid byproducts. The process may be used to produce a substantially clear solution having a relatively high percentage of potassium, and almost neutral pH, making it very suitable as a chlorine-free liquid fertilizer, for example as a foliar fertilizer, starter fertilizer, in furrow fertilizer and the like, and optionally in combination with other fertilizers. [0013] Also described herein are processes, preferably continuous, for the preparation of potassium sulfite, potassium bisulfite or mixtures thereof as a substantially clear solution having a relatively high percentage of potassium and almost neutral pH, making it suitable as a liquid fertilizer, for example as a foliar fertilizer, in furrow fertilizer and the like. [0014] Generally, the process of the present invention provides a method for preparing potassium thiosulfate, comprising the following steps: Step (la): providing a potassium hydroxide or potassium carbonate